398 



BOTANICAL GAZETTE 



[may 



of alcohol. The curves of the relative rate or respiration for 

 such higher concentrations of alcohol fall quite rapidly below the 

 normal, whereas the curves for the relative amount of respiration 

 for the same experiment may remain far above unity. 



TABLE IV C 



Two PERIODS (39.75 MIN. EACh) IN SEA WATER FOLLOWED BY 6 EQUAL PERIODS IN 

 SEA WATER CONTAINING lO PER CENT ETHYL ALCOHOL 



Solution 



Change in PH 



Sea water 



u u 



Sea water containing 10 per cent 



ethyl alcohol 



Sea water containing 10 per cent 



ethyl alcohol 



Sea water containing 10 per cent 



ethyl alcohol 



Sea water containing 10 per cent 



ethyl alcohol 



Sea water containing 10 per cent 



ethyl alcohol 



Sea water containing 10 per cent 



ethyl alcohol 



7.70-7.55 = 0.15 

 7.7o-7.55 = o-i5 



7.70-6.77 = 0.93 

 7 . 70 — 6.80 = 0.90 

 7 . 70 — 6.80 = 0.90 

 7.70—6.80 = 0.90 

 7 .70—6.90 = 0.80 

 7.70-7.05 = 0.65 



Relative rate of respiration 



0.93^0.15 = 6.2 

 0.90-i-O. 15 = 6.0 

 0.90^0. 15 =6.0 

 0.90-T-O. 15 = 6.0 

 0.80 -=-0.15 = 5.3 

 0.65 -=-0.15=4.3 



TABLE IV C CONTROL 



Eight periods (38 . 5 min. each) in sea water 



It is important to know whether or not the decrease in PH value 

 is due to the excretion of CO^ or to other acids, such as organic 

 acids which are products of incomplete oxidation. To determine 

 this pure hydrogen was bubbled through the solution (which has 

 been made more acid by Laminaria) until the excess of CO2 was 

 expelled. The solution was then allowed to come into equilibrium 

 with the CO2 of the air. It was found that in all the experiments 



